Imaging features of peripheral primitive neuroectodermal tumours.

Primitive neuroectodermal tumours (PNETs) are a rare group of extremely aggressive small round cell tumours. Most commonly, they occur within the central nervous system. However, they also sporadically involve extracranial sites (peripheral PNETs). The chest wall is the most common of these sites, the imaging features of which have been well described in earlier studies. The present pictorial essay illustrates the imaging features of PNETs at various extracranial locations.